Technical Field
The present invention relates to a grinding type vertical grain polishing machine including a resistor apparatus that restricts movement of grains and adjusts the degree of grinding of the grains when the grains are polished by grinding.
Background Art
A grain polishing machine described in Patent Literature 1 is exemplified as a conventional grain polishing machine. This grain polishing machine is described with reference to the drawings. FIG. 15 is a cross sectional view of a grain polishing unit of the conventional grain polishing machine, and illustrates part of the state where a grinding roll member is fitted to a main shaft 101. The grinding roll member is formed by alternately stacking a plurality of grinding rolls 102 and a plurality of spacers 103 in the vertical direction. In this figure, porous tubular members 105 are provided on the outer side in the radial direction of the grinding rolls 102 so as to surround the grinding rolls 102 with an interval from the outer circumferential surfaces of the grinding rolls 102, whereby a grain cleaning chamber 104 is formed between the porous tubular members 105 and the grinding rolls 102.
Each porous tubular member 105 is placed between adjacent ones of support pillars 106 that are provided at intervals in the circumferential direction. FIG. 15 illustrates four support pillars 106 and four porous tubular members 105. Then, each support pillar 106 is provided with a resistor 107 that protrudes toward the grain cleaning chamber 104. The resistor 107 serves to suppress grains from moving in the circumferential direction along with rotation of the grinding rolls 102 to thereby improve the grinding performance. The resistor 107 is an elongated member that is long in the axial direction of the main shaft 101 and is vertically placed so as to extend across the plurality of grinding rolls 102 attached to the main shaft 101.
Each support pillar 106 is further provided with protrusion amount adjusting means 108 for independently adjusting the amount of protrusion of each resistor 107 in the radial direction, and the amount of protrusion of the resistor 107 is manually adjusted (see arrows in FIG. 15). Note that, in this figure, reference sign 109 denotes a support pillar cover, reference sign 110 denotes a bran removing chamber cover, and reference sign 111 denotes a discharged grain receiver into which polished grains are discharged.
According to this configuration, the interval between each resistor 107 and the outer circumferential surfaces of the grinding rolls 102 is independently adjusted by the protrusion amount adjusting means 108 provided to each support pillar 106, and the resistance to movement (the degree of suppression in movement) of the grains in the grain cleaning chamber 104 can be adjusted. As a result, the grinding performance of the grinding rolls 102 on the grains can be adjusted at a portion of each resistor. Moreover, there is an advantage that a resistance state to a flow of the grains can be finely adjusted and changed in accordance with properties of crude grains to be polished and a shape required as a product.
Unfortunately, in the above-mentioned, grain polishing machine, the number of the protrusion amount adjusting means 108 respectively provided to the support pillars 106 is more than one (in FIG. 15, four in the circumferential direction; further, the protrusion amount adjusting means 108 may be provided at a plurality of portions in the main shaft 101 direction), and hence there is a problem that the adjustment takes a long time. Moreover, some operators may not be used to such adjustment using the protrusion amount adjusting means 108. Hence, there is a problem that, if the gap between each resistor 107 and the outer circumferential surfaces of the grinding rolls 102 is set to be extremely small, the grains are caught in the gap, and broken rice occurs if the grains are rice grains.